Cryptosporidiumspp. andGiardiasp. in Neotropical river otters (Lontra longicaudis) and giant otters (Pteronura brasiliensis) in northern Brazil

Abstract

Evaluating the occurrence of diseases in aquatic mustelids is a priority in the conservation strategies for the Neotropical river otter and giant otter. Thus, the objective of this study was to determine the frequency of infection caused by Cryptosporidium spp. and Giardia sp. in both host species in northern Brazil. The collection of biological samples was carried out in the states of Amapá, Amazonas, Pará and Rondônia, totalling 337 faecal samples of these species, which were processed using Kinyoun's technique for the identification of Cryptosporidium spp. oocysts, and centrifugal flotation in zinc sulphate solution for visualization of Giardia sp. cysts. All samples were also tested by direct immunofluorescence. The frequency of infection by Cryptosporidium spp. was higher than Giardia sp., in the two otter species. In the analysed samples co-infection by both protozoa was also found in 4.47% (14/313) of Neotropical river otter and 20.83% (5/24) of giant otter samples. Oocysts and cysts of Cryptosporidium and Giardia, respectively, may remain infectious within specific environmental conditions for long periods of time. The current identification of Neotropical and giant otters as hosts of these protozoa increases the possibility of infection in this species and the transmission of those agents to other aquatic and terrestrial organisms, as well as to human populations. The findings of this study represent the first description of Cryptosporidium spp. and Giardia sp. affecting Lontra longicaudis and Pteronura brasiliensis.

The occurrence and zoonotic potential of Cryptosporidium species in freshwater biota

“…Within freshwater and marine foraging otter populations, reported Cryptosporidium prevalence ranges from 3.9% to 41.7% [ 24 – 26 ]; our findings are at the lower end of this range, at 2.17%, but the spatial distribution of the Cryptosporidium -positive otter samples suggests that Cryptosporidium could be widespread. Although Cryptosporidium oocysts have been detected in these aquatic mustelids, the parasite species are not routinely identified.…”

“…Notably, Cryptosporidium oocysts have been reported in the faeces of four species of otter including Eurasian otter ( Lutra lutra ) (in northwest Spain), giant otter ( Pteronura brasiliensis ), neotropical otter ( Lontra longicaudis ) (both in northern Brazil) and the North American river otter ( Lontra canadensis ) (in the Pacific Northwest of the USA). All four otter species are piscivorous predators; whether these parasites can infect and multiply in these host species is unknown [ 24 – 26 ].…”

Cryptosporidium spp. e Giardia spp. em carnívoros silvestres do Estado do Pará Brasil

“…Recentemente, Borges et al (2017), utilizando métodos parasitológicos (Kinyoume parasitológico (centrífugo flutuação em solução de sulfato de zinco), analisaram 337 amostras fecais de carnívoros silvestres coletadas nos Estados do Amapá, Amazonas, Pará e Rondônia, correspondendo, a 313 Lontra longicaudis (lontra tropical) e 24 Pteronura brasiliensis (ariranha). A frequência de positividade de infecção para pelo menos um patógeno foi de 27% (94/337), ao qual a infecção por Cryptosporidium spp.…”

“…Os resultados encontrados por Borges et al (2017), assemelhamse aos encontrados no presente estudo em relação à positividade para a Giardia spp., ao qual, evidenciou-se resultado positivo para a P. brasiliensis e para a L. longicaudis tanto no método direto quando no imunocromatográfico, acreditando-se portanto, que tais espécies podem ser mantenedoras e disseminanadoras de tal agente para o meio ambiente e para outros animais. Todavia, para Cryptosporidium spp., na presente pesquisa, o resultado foi negativo em ambas as espécies, mesmo com a alta sensibilidade do método imunológico utilizado.…”